A Beginner’s Guide to - B G Structural Engineering

1 A beginner 's Guide to the steel construction Manual An introduction to designing steel structures using the AISC steel construction Manual, 14th edition. By T. Bart Quimby, , , Owner & Principal Engineer Quimby & Associates Eagle River, Alaska Professor of Civil Engineering University of Alaska Anchorage August 2011. 2nd Edition, First Printing Published by: Quimby & Associates 18110 MacLaren Street Eagle River, Alaska 99577 Email: ISBN-10: 0615521320. ISBN-13: 978-0-615-52132-9. Printed in the United States Copyright 2011. By T. Bartlett Quimby, , , All rights reserved. This hardcopy edition of the textbook may not be copied, reproduced or distributed by any means without written permission from the author. The on-line version may be freely accessed, printed, stored electronically, or otherwise distributed as long as proper credit is given to the author and there is no charge to anyone for the material.

2 The author reserves the sole right to profit from this material. Cover Photo: Providence Alaska Medical Center Addition July 2011. Structural Engineering by BBFM Engineers, Inc., Anchorage, Alaska ii A beginner 's Guide to the steel construction Manual Contents Preface .. viii Acknowledgements .. x Chapter DC: Basic Design Concepts Introduction to Design DC-1. Design DC-5. Limit State Concepts .. DC-5. Searching for the Best Design .. DC-7. ASD vs. LRFD .. DC-8. Loads and Their Combinations ..DC-13. Example Problems & Homework Problems ..DC-16. Chapter 1: Introduction Introduction .. 1-1. History .. 1-2. An Overview of the AISC steel construction Manual .. 1-3. Computational Considerations .. 1-8. Homework Structures.

3 1-9. Chapter 2: Materials steel Materials .. 2-1. Welding Materials .. 2-6. Bolts .. 2-7. Chapter 3: Tension Members Tension Member Overview .. 3-1. Slenderness .. 3-3. Tensile Yielding of a Member .. 3-4. Tensile Rupture of a Member .. 3-6. Tensile Yielding & Tensile Rupture of Connecting Elements .. 3-12. Bolt Bearing on Holes .. 3-13. Block Shear Rupture .. 3-16. Selecting Sections .. 3-20. Tension Limit State 3-22. Example Problems .. 3-24. Example Problem .. 3-24. Example Problem .. 3-34. Example Problem .. 3-37. Homework Problems .. 3-39. A beginner 's Guide to the steel construction Manual iii Chapter 4: Bolted Connections Overview .. 4-1. Mechanics of Load Transfer .. 4-4. Finding Forces on Bolts .. 4-7. Hole Size and Bolt 4-17.

4 Tensile Rupture .. 4-17. Shear 4-19. Slip Capacity .. 4-21. Bolt Summary .. 4-25. Example Problems .. 4-27. Example Problem .. 4-27. Example Problem .. 4-30. Example Problem .. 4-32. Example Problem .. 4-37. Example Problem .. 4-39. Homework Problems .. 4-42. Chapter 5: Welded Connections Introduction to Welding .. 5-1. Finding Forces on Welds .. 5-8. Effective Areas and Size Limitations of Welds .. 5-15. Effective Areas of Base Metal .. 5-17. Strength Limit State .. 5-21. Designing Welds .. 5-25. Weld Summary .. 5-28. Example Problems .. 5-29. Example Problem .. 5-30. Example Problem .. 5-31. Example Problem .. 5-32. Example Problem .. 5-33. Example Problem .. 5-36. Homework Problems .. 5-38. Chapter 6: Buckling Concepts Buckling 6-1.

5 General Member Buckling Concepts .. 6-3. Local Buckling .. 6-6. Stability Analysis Methods .. 6-9. Example Problems .. 6-10. Example Problem .. 6-11. Example Problem .. 6-12. Example Problem .. 6-15. Homework Problems .. 6-24. iv A beginner 's Guide to the steel construction Manual Chapter 7: Concentrically Loaded Compression Members Introduction .. 7-1. Slenderness Limit State .. 7-1. Limit State of Flexural Buckling for Compact and Non-Compact Sections .. 7-2. Limit State of Flexural Buckling for Slender Sections .. 7-4. Limit State of Bolt Bearing on Holes .. 7-8. Selecting Sections .. 7-8. Compression Member Summary .. 7-11. Example Problems .. 7-12. Example Problem .. 7-12. Example Problem .. 7-14. Example Problem.

6 7-15. Homework Problems .. 7-17. Chapter 8: Bending Members Introduction .. 8-1. Flexure .. 8-1. Flexural Limit State Behavior .. 8-2. Determining Applicable Flexural Limit 8-9. Flexural Yielding Limit State .. 8-11. Lateral Torsional Buckling Limit State .. 8-12. Compression Flange Local Buckling Limit State .. 8-18. Beam Shear .. 8-23. Shear Behavior .. 8-23. Shear Strength Limit State .. 8-25. Beam Deflection .. 8-27. Deflection Behavior .. 8-28. Deflection Limit State .. 8-28. Miscellaneous Beam Limit States .. 8-31. Web Local Yielding .. 8-31. Web Crippling .. 8-34. Beam 8-35. Selecting Sections .. 8-35. Cover Plates .. 8-37. Transverse Stiffeners for 8-41. Bearing Plate Design .. 8-43. Beam Bearing on Concrete or Masonry.

7 8-45. Column Bearing on Concrete .. 8-49. Beam Supporting Other Structural 8-50. Transverse Stiffeners for Concentrated Loads .. 8-51. Continuous Beam Analysis & Design .. 8-55. Bending Member Summary .. 8-55. Example Problems .. 8-58. Example Problem .. 8-60. Example Problem .. 8-62. Example Problem .. 8-63. A beginner 's Guide to the steel construction Manual v Example Problem .. 8-64. Example Problem .. 8-65. Example Problem .. 8-68. Homework Problems .. 8-70. Chapter 9: Combined Bending & Axial Forces Introduction to Combined Effects .. 9-1. The Combined Effects of Axial and Bending Forces .. 9-2. Second-Order Effects .. 9-4. SCM Appendix 8 Second-Order Effects .. 9-8. SCM Combined Force Equations .. 9-10. Example Problems.

8 9-11. Example Problem .. 9-11. Example Problem .. 9-13. Homework Problems .. 9-15. Chapter 10: Composite Beams Introduction to Composite 10-1. Mechanics of Composite 10-2. Shear Strength .. 10-3. Flexural Strength .. 10-4. Shear Anchor Design .. 10-10. Deflection Calculations .. 10-12. The Design Process .. 10-13. Example Problems .. 10-16. Example Problem .. 10-16. Example Problem .. 10-20. Homework Problems .. 10-23. References .. Ref-1. Appendices Appendix A: ASCE 7-05 Load Combinations Overview .. BGASCE7_2-1. The Load Combination Equations .. BGASCE7_2-1. Comparing LRFD & ASD Results .. BGASCE7_2-5. Example Problems .. BGASCE7_2-9. Example Problem .. BGASCE7_2-9. Example Problem .. BGASCE7_2-11. Example Problem.

9 BGASCE7_2-11. Example Problem .. BGASCE7_2-12. Homework Problems .. BGASCE7_2-14. vi A beginner 's Guide to the steel construction Manual Appendix B: Continuous Beams Introduction ..CB-1. Elastic Analysis ..CB-1. Moment Distribution ..CB-2. Finding Shear and Moment Diagrams After Obtaining End Moments .. CB-10. Plastic Analysis .. CB-10. Envelopes .. CB-11. Influential Superposition .. CB-14. Example Problems .. CB-21. Example Problem .. CB-22. Homework Problems .. CB-25. A beginner 's Guide to the steel construction Manual vii Preface The creation of the beginner 's Guide to the steel construction Manual (BGSCM) was prompted by the major rewrite of the AISC specification that appeared in the 13th edition of the steel construction Manual (SCM).

10 When textbooks were slow to respond to the change, I started thinking that a web based approach would be more responsive. After further thought the site was expanded to include undergraduate topics in Structural Engineering for civil engineers. Initially, my thought was to simply put together my 20 years of lecture notes to supplement the same wonderful textbook that I have been using for the past couple of decades. As the work got to be more extensive than a set of notes, I decided to spend the summer trying to morph this into a stand-alone on-line textbook. The next two summers saw the work expanded to include more example and home problems plus refinements recommended by users of the site. One of the recommendations was to create a hard copy version of the on-line text.